You can adjust how ads are targeted to you based on your activity off of Facebook. Notice the words "off of Facebook" Yes, it tracks on thousands of web pages, not just your on Facebook activity.
If you do not want Facebook or other companies to collect or
use information based on your activity on websites, devices, or
apps off Facebook for the purpose of showing you ads, you can
opt out from all participating companies through the Digital
Advertising Alliance in the USA, the Digital
Advertising Alliance of Canada in Canada or the European
Interactive Digital Advertising Alliance in Europe. You
can also opt out using your mobile device settings.